Antennas are typically tested before being put to use. Testing of an antenna is important for providing accurate measurements of the performance parameters of that antenna. It is very common and frequent that antennas do not perform as desired or as theoretically expected. As such, the antenna testing comes into play to measure or assess the actual performance metrics or parameters of antennas before using in the field.
For phased antenna arrays, performance parameters are typically measured over the operational bandwidth and temperature. Measuring the performance parameters involves over-the-air testing, typically done in the far field. Traditional antenna metrology requires expensive, large test stations—for example far-field anechoic chambers or compact range. The traditional approaches for performing factory acceptance testing are adequate in low-volume markets (e.g. fire-control fighter jet radar phased arrays) but are completely inadequate in high-volume markets (e.g. 5G base station phased arrays) or moderate-volume markets (e.g. airborne sitcom phased arrays). In particular, most traditional testing techniques are expensive, require relatively large testing space, and may not be adequate to perform some performance measurements.
Anechoic chambers, which are commonly used in testing phased antenna arrays and other antennas can be costly. The cost usually increases with size of the chamber. Also, most testing equipment can be costly and difficult to control or monitor. Such difficulty can make the testing process slow, therefore, adding more to the total cost.